Perl 5 kept single quotes (') as package component separators in order to remain backward compatible with prior perls,
but advocated using double colon (::) instead.
In the more than a decade since Perl 5,
double colons have been overwhelmingly adopted and most people are not even aware that the single quote can be used in this manner.
So,
unless you're trying to obfuscate your code,
don't use them.